1. Technical Field
The disclosure relates generally to measurement systems, and more particularly, to calibration of measurement systems.
2. Background Art
Calibration of measurement systems used in, for example, measuring IC chips during or after manufacturing, is essential to attain accurate measurements. Current practices of checking linearity and calibrating vertical displacement of a measurement tool use several step height standards. The same is true for horizontal displacement. That is, the tool is used to measure a number of structures having known heights or known pitch standards for horizontal displacement. Limitations on the availability of these standards and the uncertainty of the standards make this approach inadequate.